Aluminum Eddie heads

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CUDACOX

CUDACOX

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Just wondering if a pair of RPM aluminum heads and Air Gap intake would make much difference bolted on my 340 compared to the stock steel heads and LD340 intake.I was thinking about changing the cam as well to a 484/284 purple shaft I have new in box.I know everyone will want more info on my motor,but it's just a mild street 340 and I run 68-70 stock 340 manifolds with stock 2" exhaust.. Any comments will be appreciated..Thanks in advance!
 
I went through this same decision a couple months ago. I built a mild 440, and for me the $1500 price for maybe 25-30hp gain just wasn't worth it. If your iron heads are in good shape and don't need a complete rebuild I would stick with them.
 
Thanks for being the first to jump in! I already bought the heads and intake.New in the box from a guy that bought them a few years ago and never took them out of the box.I just cound't say no to the price! Almost half price! My motor is fresh,about 1000 miles and my valves make a little ticky noise so I was going to install lash caps.I figure change everything including the cam and it would wake it up..Thanks again..
 
The question is, can the iron heads be redone to match the flow abilty of the Edelbrock head for the intended cam to be used at a equal or cheaper price? The LD-340 is slightly shorter with runners not quite as good in terms of smooth traveling but they are larger. This makes that intakes air fuel charge slight slower but surely capable of excellent power.

IMO, the cam your looking at is in need of headers and 2-1/2 exhaust. With well prep'd heads, you cam make well over 400 HP. (With headers) if your going to stay with exhaust manifds and the 2 inch exhaust pipe, look I to a split duration cam. Comp cams has a line designed with exhaust manifolds in mind. Very long exhaust duration.
 
Use headers with the combo. You'll be making over 400 HP with that set up.
 
Other than slightly better flowing air movement, the biggest advantage of aluminum heads is that they cool off the engine better, so you can go up in compression ratio. If you aren't increasing the compression ratio, then you may get a zero net HP gain due to the cooling effect. This is offset by the better flow rates, so essentially no difference between these and stock heads IMHO.
 
rumblefish360 said:
The question is, can the iron heads be redone to match the flow abilty of the Edelbrock head for the intended cam to be used at a equal or cheaper price? The LD-340 is slightly shorter with runners not quite as good in terms of smooth traveling but they are larger. This makes that intakes air fuel charge slight slower but surely capable of excellent power.

IMO, the cam your looking at is in need of headers and 2-1/2 exhaust. With well prep'd heads, you cam make well over 400 HP. (With headers) if your going to stay with exhaust manifds and the 2 inch exhaust pipe, look I to a split duration cam. Comp cams has a line designed with exhaust manifolds in mind. Very long exhaust duration.
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* I was wondering when you were going to chime in! Thanks buddy..The thing is..I have all these parts sitting around now and if I can get more HP I want to go with it.I'm putting the stroker on the back burner not enough $..Just how much difference do you think it would make with these bolt on parts??
 
68gtxman said:
Other than slightly better flowing air movement, the biggest advantage of aluminum heads is that they cool off the engine better, so you can go up in compression ratio. If you aren't increasing the compression ratio, then you may get a zero net HP gain due to the cooling effect. This is offset by the better flow rates, so essentially no difference between these and stock heads IMHO.
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* Being closed chamber heads,would the C.R. not be increased with the RPM's?
 
CR has nothing to do with RPMs, but you are correct that if the size of the chambers in the aluminum heads are smaller than the stock heads, the CR will be increased. But to get the most benefit, you need approx. 1.0 increase in compression ratio to start seeing a good difference in HP when switching from cast iron to aluminum.

Since you've already bought them, I'd use them! Good luck and have fun!
 
68gtxman said:
CR has nothing to do with RPMs, but you are correct that if the size of the chambers in the aluminum heads are smaller than the stock heads, the CR will be increased. But to get the most benefit, you need approx. 1.0 increase in compression ratio to start seeing a good difference in HP when switching from cast iron to aluminum.

Since you've already bought them, I'd use them! Good luck and have fun!
Click to expand...
* Thanks! by RPM'S I ment the RPM heads..Closed chamber compared to open chamber steel heads..Thanks..
 
With exhaust manifolds in use? I don't know.

The static compression ratio does not increase with the RPM's.
The dynamic compression ratio can increase with RPM's. it will have to be the cams fault (if you will) that the ratio increases due to the ramming effect of the higher engine speeds. This happens anyway though a proper cam can add more and fuel into the cyclinder.

Do not enter this into the equation when it comes to fuel and power figures. There are to many variables for your head to sort through. This is what dyno's are for. The only thing you are concerned about, and this is nothing more than a tried and true method, is for you to use the K.I.S.S. method. Keep It Simple Silly.

As a general base line, we know that 87 octane can support a 8.5-1 ratio engine no problem. Adding performance parts change nothing if the ratio has not changed or the cam remains the same or very close to stock. It does allow for more a effective air pump to operate and more air and fuel in and out which is why power increases.

Adding a aluminum head changes little. We know that it has the ability to disparate heat faster. I do no and can not subscribe to this as cooling the engine in any way shape or form.
Also, it can allow for a slightly higher comp ratio. This is approx. 1pt higher. This is a base line in the KISS method.

Due to the way aluminum acts on a engine, you can go up that 1pt. without a change in fuel grade.

Changing the cam can lower dynamic ratios in the low RPM range due to the design of the cam which will bleed off some compression. This is why a milling of the heads or piston replacement comes into play.

Sorry, I was on the phone typing out a bit more reply when things went berserk.
 
Yeah, if you've got them, and at a great price, by all means USE THEM. Lol
 
I got'em,wanna use'em...I think even the less weight will be good as well! I have the Comp Cams XE274H cam in it now.I always liked the 284/484 Purple shaft..
 
Do your pistons stick out of the hole? The high-performance 340 ones usually did. If they do you may need to use a thicker head gasket with the closed chamber eddie heads.

I agree on keeping the comp cam.
 
Don't forget that the eddy heads have a max lift of .575" (stock) you unless you don't have the room (piston to valve clearance) you're leavening a lot on the table.
Now motor has a @50 231/239 .525"/.550" with 110lsa with the same top end you have sitting in a box (I also have headers).
 
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